Blog

When to Plant Lemongrass in Tillamook County, OR

Tillamook County, Oregon Zone 9a May

Your May game plan for Tillamook County, Oregon

Your garden in Tillamook County, Oregon is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 19
Avg. first frost October 29
Soil temp (4") 71°F
Watering High
Pest pressure High
Daylight 14.7 hrs
  1. Begin indoor sowing: lemongrass

    These need a head start before your last frost (April 19). Sow into cells now so you're ready to transplant in a few weeks.

Instant PDF download. No spam, unsubscribe any time.

Lemongrass is a tropical grass with a strong citrus aroma used extensively in Southeast Asian cuisine. The swollen stem bases are the most flavorful part.

Tillamook County, Oregon is in USDA Zone 9a. The average last spring frost is April 19 and the first fall frost is October 29, giving you a growing season of approximately 193 days.

At an elevation of 332 feet, Tillamook County receives approximately 40.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Lemongrass during the growing season.

Tillamook County, OR (Zone 9a) Moderate season
193 days
Last Spring Frost April 19
193 growing days
First Fall Frost October 29
Share this guide:

Tillamook County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (20 days to spare)
Start indoors: Mar 1 Transplant: Apr 19 🍅 Harvest: Jul 5 – Oct 4
Recommended (50%) ✓ Fits season (18 days to spare)
Start indoors: Mar 8 Transplant: Apr 26 🍅 Harvest: Jul 12 – Oct 11
Safe Start (90%) ✓ Fits season (17 days to spare)
Start indoors: Mar 27 Transplant: May 15 🍅 Harvest: Jul 31 – Oct 30

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Tillamook County

How your county's soil matches Lemongrass's growing requirements.

Soil pH

Your soil pH (5.3–6.5) overlaps with Lemongrass's range (5.5–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Tillamook County is excellent for Lemongrass — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.3%) — Lemongrass will thrive.

How to Plant Lemongrass

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Lemongrass

2
successive plantings in your 193-day season

Sow every 8.6 weeks. Last sowing by Jul 01 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,051 gal / 100 sq ft

Monthly Watering Guide for Lemongrass

Lemongrass needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Lemongrass Needs Rainfall You Supplement Action
Jan 5.4" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 6.5" 3.4" 3.1" 💧 Light watering
May 6.5" 2.5" 4" 🚿 Regular watering
Jun 6.5" 1.8" 4.7" 🚿 Regular watering
Jul 6.5" 0.7" 5.8" 🚿 Regular watering
Aug 6.5" 0.8" 5.7" 🚿 Regular watering
Sep 6.5" 1.8" 4.7" 🚿 Regular watering
Oct 6.5" 3.7" 2.8" 💧 Light watering
Nov 6.4" 0" ❄️ Dormant
Dec 6.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Tillamook County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Lemongrass Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Lemongrass needs ~1,341 GDD — county provides 2,653 GDD Excellent fit

Lemongrass Planting Timeline — Tillamook County, OR

Lemongrass Planting Calendar

Activity When Date Range
Start Indoors March 8 Mar 8 – Mar 22
Transplant Outdoors April 26 Apr 26 – May 10
Direct Sow April 26 Apr 26 – May 17
Harvest July 12 Jul 12 – Oct 11

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Harvest
August Harvest
September Harvest
October Harvest
November
December
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

75–120 days

🧪 Soil pH

Needs 5.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9a

📆 Growing Season

193 days in Tillamook County

Growing Tips for Lemongrass in Tillamook County

Direct sow Lemongrass outdoors after April 19 in Tillamook County when soil has warmed and frost danger has passed.

Common pests for Lemongrass in this region include corn earworm and corn borers. Use row covers early in the season and inspect plants weekly.

General growing tips

Start from divisions or store-bought stalks rooted in water. Grow in rich, moist soil with full sun. In cold climates, grow in containers and overwinter indoors.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lemongrass in Tillamook County, OR?

Tillamook County is in Zone 9a with an average last frost of April 19. Plan your Lemongrass planting based on this frost date — see the calendar above for exact timing.

What planting zone is Tillamook County, OR?

Tillamook County, Oregon is in USDA Hardiness Zone 9a. The average last spring frost is April 19 and first fall frost is October 29.

🌱

Your Tillamook County Garden Planner — Free

A 24-page printable planner built for Tillamook County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Tillamook County, OR. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.